Patent GB-883414-A (GB)
Title: Improvements in and relating to structure supporting linkwork assemblies
Inventor: SEYMOUR DOUGLAS FRANK
IPC: G21C5/08
Filed: 1957-01-04
Abstract: 883,414. Bracing for nuclear reactors. ENGLISH ELECTRIC CO. Ltd. Jan. 2, 1958 [Jan. 4, 1957], No. 509/57. Class 20(2) [Also in Group XL(a)] A linkwork assembly for applying external support to a body or structure comprises a plurality of link members disposed end to end so as to encircle the structure with clearance therefrom, the adjacent ends of each pair of adjacent links being pivotally connected to an outwardly extending coupling member which is in turn pivotally connected to an inwardly extending support means at a position spaced outwardly from the adjacent ends so that external pressure is applied to the structure through the inwardly extending support means, the link members being free to move circumferentially relative to the body whereby to substantially equalize the tensions in the respective link members. In Fig. 1 the moderator structure 10 of a nuclear reactor is supported externally by a number of linkwork assemblies, one of which is shown in the figure. Each pair of adjacent links 15 is connected by a single pivot pin to two outwardly extending coupling members 13, one above and one below the ends of the links. The outer ends of each pair of members 13 are pivotally connected by a pin 12 to a U-shaped bracket 11 extending inwardly within the closed linkage and carrying at its inner ends a support plate 11a which bears against the external surface of the moderator structure. The support plates 11a extend just less than half way along each face of the moderator and adjacent ends of adjacent support plates are connected loosely together by sliding joint plates 11b which are arranged to allow normal movement of the support plates as the moderator structure changes in size and shape during normal operation but, in the event of one of the link members breaking, to limit the separation of the associated support plates and to carry at least part of the load normally carried by the broken link. Each coupling member 13 may be provided with abutments (not shown in Fig.) which engage with abutments on the ends of the link members to limit relative angular movement if one of the links breaks so that some tension remains in the linkwork. The tension of the linkwork may be adjusted by turnbuckles 16, or by providing means for varying the effective length of coupling members 13 or the radial distance of pivot 12 from the support plates 11a. The coupling members 13 may be replaced by triangular coupling members, the link members being pivoted to each corner of the base of the triangle and the coupling member to the apex; the base of the triangle should be less than half the height. In another arrangement, Fig. 5, pairs of link members 115, are connected by a pivot pin 114 to an outwardly extending coupling member 113 which is in turn connected by a pivot pin 112 to a pair of diamond shaped side plates 111; the side plates 111 are connected at each end to a U-shaped support beam 111a by pins 117 which are firmly located in the support beams but which pass through slotted holes 118 in the side plates. The slotted holes allow normal movement of the support beams but in the event of one of the link members breaking the support beams carry part of the load previously carried by the broken link. The pivot pin 114 is extended on either side of the ends of the link members so as to pass through slotted holes 119 in the side plates 111, these slotted holes being arranged to limit the relative angular movement of the coupling members and the link members should one of the links break.